Dave Jones

so some more fag packet math: Assume a single 300L tank. Based on incoming mains temperature 8C. Step1: Target for the ASHP to increase the cylinder temp to 45C an increase of 37C. Would use 12.9 KWH of electric. At 6kw of power per hour from the ASHP would take 2.14 hours. Step2: Target for the immersion to increase cylinder temp to 65C and increase of 20C. Would use 6.9kwh of electric. At 6kw immersion would take 1.16 hours. Not factored in the heat recovery but would make step 1 much faster. So not an insurmountable task ? thats if my math adds up.....

this is the waste water heat recovery unit im planning on using. basically plumbing all the shower wastes to it. https://recoupwwhrs.co.uk/documents/Recoup_Pipe_HEX_Be-Technical_Specification.pdf

all the showers waste water will be run through a waste water heat recovery column which feeds the tanks. All helps right

wont find a decent trade on day rate.

already have the Powerwall, will be taking it from our existing place. will be fitting approx 9kw of solar as its relatively cheap and quick payback. yes 3 phase (all new builds in western powers area are required to be 3 phase now). must be a calculator somewhere that tells how long to heat X volume of water to X temp in kwh .....

its a very nice feeling!

depends how much energy and time you want to expend, you could get someone (surveyor so his report is recognised by the court) to list all the stuff thats wrong. Get it quoted by someone, preferably two other builders. Ask the original guy to make good in line with surveyors report, work to be inspected prior to completion. If at this point you get radio silence then its off to small claims. very very simple process.

did you need building regs on the extension ?

my back of a fag packet design is for the ashp to provide low temp heat (45) during off peak hours until the tanks are all at 45, then immersion them upto 65/70 again off peak so that the ashp can return to providing heating. This way tanks will be ready for the morning showers. Daytime solar into the ashp to get the tanks back to 45, any exces solar into the tanks as well and when they done to the tesla powerwall. During the winter when not much PV, id use the tesla to provide power during expensive times. What size of heat pump should I be looking at, bigger is better ? Workable ?

unfortunately another bad move. A site toilet is all thats needed. Trades shouldn't be leaving tools on site to get pinched, and if they do are you now liable for them as its your shed ? All these little mistakes snowball.

id like not to admit defeat quite yet and say ASHP aren't capable of the job.

who provided the cabin ?

agree ref shower its a preference as there is no shortage of water in the UK.

previous house was 2 x gas system boilers, worked perfectly. Switching to electric only to save the planet etc

fischer are very good, i really like their hammer in fixings for screwing studs to blockwork.

we are fitting a 32mm main to replace the old lead pipe. 1L/sec but accumulator tank may be needed your right.

I need to provide for 4 showers happening at the same time, the washing machine and dishwasher on at same time. The showers are decent 20L/min so wont take long to empty a small tank. Coming from limitless hot water I'll need to keep adding tanks until it doesn't run out from our usage pattern. The mixergy tank looks good for a 'primary' tank but there doesn't seem to be a lot of reviews on it. My heatloss calcs show minimal heating requirement of 6.6kw for an outside temp of -15C, want to make sure i size the ASHP for hot water production as efficiently as possible. Not sure if it makes sense to use the excess solar to drive an immersion as if it were to drive the ASHP then each kw of solar would be 3 or 4 kw of heat right ? Finding a plumber locally who knows enough to design this setup is seemingly impossible, ive emails into vaillant and samsung asking their recommendations.

heat pump in reverse.

some heat pump cylinders do not need a separate ufh manifold pump, seen a couple installed.

crates work fine with upstream sediment catchers.

Looking to maximise efficiency for our hot water setup for our in progress build. Will have 3 x 300L tanks, one of them has the heat exchanger for heat pump. It's a lot of tanks but that's how much is needed to cover peak useage + 25% margin. 9kw solar on roof. Time of day tariff. The ASHP flow temp target is 25-30c (UFH temp) so that alone wont be enough to heat the tanks. Looking at a solar pv divert to dump excess solar into the main tank when its available and top up overnight on cheap rate. Assume we need some sort of pump to mix all three tanks controlled by a stat ? Whats the best scop heat pump out there at the moment ? Plumber is advising samsung and daikin.

infra red panels are a total con job. Avoid. See what the heatgeeks have to say about them on youtube.

send the cold water through the slab UFH as well.

have you got a heat pump and mvhr ? If so fit a chiller unit and drive the heat pump in reverse.

massive mistake not getting a price. however. Turn this around and see if the builder is up for a deal. Tell him you will pay your original estimate in full, in stages against work done. This gives him the opportunity to earn more by working normally instead of day rate and you lose the hassle of checking what your not qualified to check and the hassle of knowing you are being robbed. If he doesnt bite at this then you know 100% your budget is not enough and they will be gone once the cash runs out.